It also helps that most "lunch" places put calories up (at least near where I work). You can at least figure what the "best choices" are. Ordering ahead is neat trick!
That's the real kicker - be aware of what you're eatings calories. A Big Mac from McDonald's can be less calories than a 6" from Subway, depending on the choices you make as far as toppings. Just because it looks healthy doesn't mean it's a better choice for weight loss.
And when you do, make the best choices you can.
Whenever I get that feeling of "I can't eat my healthy lunch one more day" I order Chipotle tacos, no sour cream, no cheese, no soda, and no chips.
By ordering ahead I'm never tempted to say "yes" to chips and salsa, and I never get distracted and go to Sonic for a burger and tots instead.